A longtime Fairfax County teacher has been charged with giving marijuana to a Chantilly High School student Friday in a school hallway, county police said.

Thomas Newlun, 53, a special education teacher who has worked at five Fairfax schools since 1989, was arrested early yesterday at his home in Marshall, in Fauquier County, police said.

Newlun gave a small amount of marijuana to a 17-year-old student about 11 a.m. Friday during a break between classes, police said. Officer Richard Henry, a police spokesman, said the teenager and a friend took the drugs to a school security officer, who alerted police.

Henry said investigators don't think other students were involved. "There is no indication that this has happened before," Henry said. Police did not say why Newlun gave away the drug or how he got it.

Newlun did not return calls yesterday. He is on administrative leave without pay until the investigation is completed, a schools spokesman said.

Chantilly High Principal James Kacur referred calls to the school system's public information office. In a letter to parents, he said classes have not been disrupted.

"We know that you are concerned for the safety of your children," Kacur wrote. "Please remind your child that he or she should never take any kind of drug and should always report suspicious activity to a trusted adult.

"I want to commend our students and staff for handling this inconvenience calmly," Kacur wrote.

County schools spokesman Paul Regnier said that other than a break of about a year in the early 1990s, Newlun has worked in county schools. He had taught at Edison, South Lakes, Woodson and Westfield high schools and has been at Chantilly since 2002.

Newlun is charged with distribution of marijuana to a minor, drug distribution on school property and contributing to the delinquency of a minor. Fairfax police said that Fauquier sheriff's deputies arrested Newlun about 1 a.m. yesterday and that he has been released on bond.

"I am confident that our principal, Mr. Kacur, and the Fairfax County public schools system, will handle this situation with the best interest and safety of our children in mind," PTSA President Patty Huba said.